Vacuum cleaner



FIG. 1 is a left-side elevational view of a vacuum cleaner showing our new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a right-side elevational view thereof; and

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a vacuum cleaner, as shown and described. 